Campbell Scientific CPEC200 Closed-Path Eddy-Covariance System - Manual (Page 78)

Appendix C. Output Variables
TABLE C-1. Values stored in table ts_data
Compile
Switch
Variable
Name Units Description
cell_press kPa Pressure in the sample cell
diff_press kPa Differential pressure (sample cell, relative to ambient)
pump_flow LPM Sample pump speed, converted to volumetric flow rate
V valve_number Valve number (0 to 6); determines which zero/span valve is
selected
V valve_flow LPM zero/span flow
D CO2_signal Relative strength of the infrared signal in the CO
2
absorption
band
D H2O_signal Relative strength of the infrared signal in the H
2
O absorption
band
D source_tmpr ºC Temperature measured inside the source housing
D pump_control Pump speed control variable; can be from 0 (off) to 1 (full speed)
D pump_press kPa Pressure measured at the sample pump inlet
D pump_tmpr ºC Temperature of the pump
D ControlBits Status of heaters and fans (see Appendix D, Control Bits, for
details)
D, V SequenceStep Status of the zero/span sequence (see TABLE 6-1 for details)
D, V valve_tmpr ºC Temperature of the valve module
D, V valveControl Zero/span flow control valve; can be from 0 (closed) to 1 (open)
D, V, S scrub_press kPa Pressure measured at the scrub pump outlet
D, V, S scrub_tmpr ºC Temperature of the scrub module
D BattVolt V Supply voltage; measured inside datalogger after diode voltage
drop
D process_time µs Time to process the scan (a copy of ProcessTime from the Status
table)
D buff_depth Number of scans in the pipeline buffer that have not yet been
processed (a copy of BuffDepth from the Status table)
flux
The online flux calculations are stored in table flux. A record is written to this
table at the end of every output interval (30 min). Space is allocated on the
memory card for 9,600 records (200 days at one record per 30 min). The CPU
has storage allocated for 480 records (10 days).
Most of the values stored in table flux are always stored, but some are
dependent on the settings for program constants. See Section 5.4.2 Compile
Switches, for details on setting program constants.
The first six values ( Hs through u_star) are the basic online flux calculations.
The next five values ( Ux_Lag_Avg through sonic_samples) are averages of
the sonic anemometer outputs. These are averages of the values that have been
lagged to align the sonic and IRGA data. They are filtered to include only
those data for which there are no sonic diagnostic flags.
The next six values ( CO2_Lag_Avg through irga_samples) are the
corresponding lagged averages of the EC155 data.
The next two values ( pump_flow_Lag_avg and pump_OK_samples) are the
corresponding lagged averages for the pump flow.
C-2